Your Spire Stone communicates with your phone via the power efficient Bluetooth Low Energy protocol and only does so in batches. This standard performs far better than older Bluetooth devices when it comes to battery drain.
Using the Spire Stone app will have a minimal effect on your phone's battery life. However you should be aware your phones power settings, the number of app's you are running, and your data use, all impact battery life.
At Spire Health, our engineers are highly focused on ensuring battery life optimization. We use our phones as much as you; nobody wants a dead battery!